United States | News & Politics

In the complaint, the Department of Justice alleges Mangione kept a notebook in the months leading up to the fatal shooting, writing in an Aug. 15 entry that “the target is insurance.” Mangione allegedly wrote that an attack on an insurance company "checks every box."

In a later entry that federal authorities cited in the complaint, they claim that Mangione marveled at his luck upon discovering the New York conference outside of which Thompson was killed.

“This investor conference is a true windfall ... and — most importantly — the message becomes self-evident,” the notebook read.

Prosecutors further allege the notebook “describes an intent to ‘wack’ the CEO of one of the insurance companies at its investor conference.”